FAYETTEVILLE, Ark. – Arkansas running back Michael Smith still remembers when he couldn't even win a race with his sister. He will spend this fall trying to outrun the shadow created by two famous predecessors.

Smith ranks among the shortest players in college football, but nobody in the nation has bigger shoes to fill. Smith, a 5-foot-7 junior, has the unenviable task of stepping in for first-round picks in Darren McFadden and Felix Jones, who combined to rush for more than 2,800 yards in each of the past two seasons.

He won't have to face that burden by himself because Brandon Barnett and converted linebacker Chip Gregory also will get plenty of carries in an offense that shouldn't be quite as run-oriented under new coach Bobby Petrino. True freshman De'Anthony Curtis, a four-star prospect and Rivals100 selection, could enter the mix when he arrives on campus this summer.

But it's the diminutive Smith who exited spring practice as the Razorbacks' top running back after rushing for 157 yards and a touchdown in Saturday's Red-White Game.

Smith said he learned plenty about the game by watching those two 1,000-yard rushers from the sideline. He admired their speed, fearlessness and upbeat approach.

"They always had a smile on their face even if things were going bad," Smith said. "It was always like they were in the backyard playing football. They had fun doing it, and that's why they were very successful."

Smith also constantly wears a smile that masks a chip on his shoulder that grows bigger whenever he hears he's too small to play big-time college football. Smith's competitive streak arose during his childhood races with his sister, Loreal, who is two years older.

The siblings often raced each other while growing up as part of an athletic family in Tallahassee, Fla. Their father played football at Florida A&M from 1981-84 and their mother was a former star high school sprinter who went on to coach them in track.

"With me and Michael, everything was a competition," said Loreal, a sprinter and hurdler for North Carolina A&T's track team. "He was a guy, but I was the oldest. Being a guy, he felt like he had to outdo me in everything, but at the time I was faster than him."

Smith didn't actually beat his sister in a race until he reached middle school. He said the embarrassment of losing those races got even worse when his sister talked trash after her victories.

STEPPING IN THEIR SHOES

Five running backs were selected in the first round of the NFL Draft. This chart reveals how their former college teams will try to replace them.

Jonathan Stewart, Carolina, 13th overallThe skinny: Stewart's decision to turn pro early should create an immediate opportunity for junior college transfer LaGarrette Blount. Blount, who has admitted one reason he chose Oregon is because of the Ducks' uniforms, ran for 68 yards on five carries in the spring game.

Rashard Mendenhall, Pittsburgh, 23rd overallThe skinny: Junior Daniel Dufrene is the most experienced candidate, but he spent too much time dancing this spring instead of immediately hitting the hole. He probably will split carries with true freshmen Mikel LeShoure and Jason Ford. Don't be surprised if star receiver Arrelious Benn also spends time in the backfield.

"If I could have beaten her up, I would have beaten her up," Smith joked, "but she was always bigger than me, so I couldn't beat her up.

"She always had something to say, but I think it made me tougher in the long run.''

That toughness has helped Smith overcome his lack of height. He tore an anterior cruciate ligament late in his junior season at Tallahassee's Rickards High and hurt his ankle the following year. Over and over, he has shown his willingness to withstand pain.

"As a little guy, the first question (about me) is always going to be, 'How tough is he?' " Smith said. "I had to build a tolerance to pain in everything I do. Little nicks and bruises couldn't sit me down."

Smith proved last week that he could deal with health problems much more serious than mere nicks and bruises. He averaged more than 12 yards per carry and caught three passes for 63 yards as arguably the top performer in the Red-White Game. If those numbers don't seem impressive enough, consider that he put up those totals while running with a hernia that required him to undergo surgery Thursday.

"You've got a guy over there with hernias coming out there running full speed and busting it," Arkansas wide receiver London Crawford said. "That comes from coaching and growing up and having mental toughness."

Smith decided not to let the injury sideline him last weekend because, in part, he wanted to earn that kind of respect from his teammates.

"To be honest, there was a time I was just going to sit it out and have the surgery, but Coach emphasized he needs leaders," Smith said. "In order to be a leader, you have to be out on the field.''

Of course, that Smith already has dealt with a serious knee injury and a hernia raises the questions of whether he can withstand the physical pounding that comes with playing in the Southeastern Conference.

Short players have succeeded in SEC offenses before. LSU won a national championship in part because of 5-5 dynamo Trindon Holliday, whose world-class speed allowed him to make big plays out of the backfield and in the slot.

But the Tigers used Holliday as a change-of-pace threat who never carried the ball more than six times in a game. Smith probably will touch the ball a whole lot more than that, particularly after his eye-popping performance in the spring game.

"He made some great plays," Petrino said. "It's great to see his speed show up, (see how) he keeps getting more attempts and the explosiveness that he can have. I've just got to learn how to use him right and make sure we throw him the ball enough, get him in the open field. He certainly showed he can run with the football."

Smith doesn't want to speculate how many carries he might get each week. He just says he's ready for any assignment the coaches give him. "I'll run until my legs fall off," he said. "I like to think I'll keep on trucking 'til I can't go anymore."

Nobody expects Smith to match the accomplishments of McFadden or Jones. The lessons of 2007 also should remind Arkansas fans not to get carried away by Smith's spring performance.

He also performed well in spring practice last year and rushed for 143 yards on eight carries during one scrimmage. But Smith couldn't translate that spring success into a featured role last fall. He ran for 303 yards on 46 attempts.

Smith's history of injuries and lack of height make him seem like a less-than-ideal replacement for a tandem as talented as McFadden and Jones. The uncertainty in the backfield is a major reason few people expect Arkansas to contend in the SEC West.

But the skepticism surrounding Smith only makes him work harder. That's been part of his nature since he was growing up in Tallahassee.

As much as the athleticism of his parents helped his speed, their lack of height assured he'd always be looking up at his teammates and competitors. Smith's father, also named Michael Smith, said he's 5-8 and his wife is only 5-5 or 5-6.

"I think that just helped fuel him," said the elder Smith, who was a wide receiver and kick returner at Florida A&M. "(He thought) maybe he's got to take one more rep, do one more conditioning drill or do things a little differently because his genes made sure his size was always going to be a factor."

Smith's family background might not have allowed him to develop physically as much as he wanted, but it sure helped build his competitive fire. Every time he outruns a defender, Smith owes a bit of thanks to his older sister. All those times she outraced him during their childhood, he never thought about quitting. The frustration of repeatedly finishing second only made it that much more rewarding when he finally sprinted past her for the first time.

"She didn't believe I could outrun her," Smith said. "It was a 50-yard dash, and she said I cheated or something. But I beat her, and I've beaten her every time since."

Smith has continued proving people wrong ever since. He sees no reason to stop now.